Benjamin broido



May 25. 1931- B. BRoIDo l Re. 18,0 82

` RADIANT SUPERHEATER Original 'Fied llarch l5 1925 A TTORNEY ReissuedMay 26, 1931 UNITED STATES PATENT OFFICE BENJAMIN BBOIDO, DECEASEII),LATE OF NEW YORK, N. Y., BY THE SUPERHEATER COM- PANY, F NEW YORK, N.Y., ASSIGNEE RADIANT SUPERHEATER `Original No. 1,590,180, dated June 29,1926, Serial No. 625,418, led March 15, 1923. Application for reissueled March 26, 1931.

This invention relates to superheaters of the type which has becomeknown as the radiant type of superheaters. These superheaters areexposed to the direct radiant .heat of the fuel bed and burning gases inthe furnace and by far the biggest part of 1 the heat given up to thesuperheating surface reaches it by direct radiation and only acomparatively small part is absorbed from 1() the hot gases bconvection. This type of superheater di ers materially in a number ofrespect from superheaters in which the main portion of the heat isdelivered up to the superheater through convection and involves entirelynew and difficult problems.

Among them is the important one of protecting the superheater against atoo intense heat of radiation.

The object of the present invention is to provide a novel and elicientway of protecting the superheater of the radiant type against heat whichmay prove too intense and which may endanger the life of the superheaterelements.

Si The invention is illustrated in the accompanying sheet of drawingswhere Fig. 1 is a longitudinal vertical section through a water tubeboiler in the fire box of which there is found a superheater protectedvby my novel device; Fig. 2 being a sectional view on line 2 2 of Fig. 1.

The boiler in connection with which I illustrate my invention is ofausual type and is used for illustrative purposes only.

It will be clear from what follows that my invention may be used inconnection with boilers of a great many different types. The boilerillustrated comprises a setting 1 within which is located the furnace 2at the rear of which there is a bridge-wall 3, the boiler proper beinglocated above the furnace.

Front and rear water legs 4 and 5 respectively are connected by thewater tubes 6 and communicated at their upper ends with steam-and-water.drum 7. Baling 8 directs thel gases from furnace 2 over the water tubes6 on their way to stack connection 9.

Steam is taken 0E from the boiler at 10 and 5o carried through the pipe`11 either directly Serial No. 525,628.

or through the superheater to the point of consulnption.

Ars far as described, this boiler is of an ordinary construction. Thesuperheater to which I wish to apply my invention is associated with therear wall 12 of the setting although, as will be clear as thedescription. proceeds, it might be located in oneof the other walls orat some distance from the walls. It comprises the two headers 13 and 14which are connected by a series of pipes or superheater elements 15. Theheadersy 13 and 14 lie outside of the boiler setting and the pipes 15each have appropriately shaped ends to connect with these headers, themain portion `of the pipes 15 lying within the.

setting and in close proximity to the wall. Steam is carried by pipe 11to the header 13 and is taken off from the header 14 at the point 16.The precise shape or construction of the pipes or elements 15 is immate--rial as far as my invention is concerned.

For purposes of illustration I show them as consisting substantially ofstraight bare lengths but they might be covered with protecting coveringor they might equally well have some dili'erent shape. They mightlikewise, within the scope of the present invention, be parallel to thewall but at some angle to the vertical.

It will be noted that the superheater elements 15 are not struckdirectly by any of the hot products of combustion from the l furnace asthese pass through the boiler to the stack but on the contrary derivepractically` all of their heat from the fuel bed and from thehot gasesby direct radiation only. The condition to which they are suby jected issevere and it has been found'that even when supplied with a protectivecovering they are apt'to deteriorate vary rapidly. To interpose a screenor' wall ofV anyl kind whichl would completely protect them against theradiant heat would defeat the very purpose of locating the superheaterat'` this point. Nevertheless, some protection has been found essential.I am aware that it has been proposed to protect them by means ofvertical tiers of bricks located between ythe elements and protrudingsomewhat beyond them toward the furnace. These bricks are supposed tomitigate somewhat the intense radiant-heat but as they themselves becomeincandescent they impart a great deal of heat to the superheaterelements.

I purpose to provide a series of water tubes 17 for this requiredprotection. These water tubes 17 are generally shaped like thesuperheater elements 15, having a straight length and two bent ends, thelatter communicating with the headers 18 and 19. The header 18communicates by means of pipe 2O with the steam drum 7, while the header19 is connected to the water leg 5 by the pipe 21. The lower header 19is supplied with valved pipes 22-22, so that accumulations of sedimentcan be blown olf from time to time. The lengths of the water tubes 17are alined in a plane somewhat closer to the furnace than thesuperheater elements 15. It will be noted, however, that they do not liedirectly in front of the superheater elements but are arran ed directlyin front of the alternate spaces etween the superheater elements. Inthis manner they do not shut olf to any appreciable extent the radiationfrom the furnace. The protection they afford, however, is suiicient toinsure prolonged life to the superheater elements. As above pointed out,bricks in a similar situation radiate a large amount of heat to thesuperheater elements, and the result is that their protection isconsiderably offset. While, of course, the water tubes 17 also radiateheat they are kept at comparatively low temperature by the watercirculating through them and, therefore, will absorb much more of theheat radiated by the superheater elements than they in turn give out tothe latter by their own radiation. The pipes 17 are filled with boilerwater and are in effect a portion of the boiler system, and a certainamount of Vsteam will be generated Vin them. This will circulate upwardthrough pipe 20 and reach the steam and water drum 7,-new water beingsupplied to the lower drum by Ipipe 21.

While show only one row of water tubes communicating with the boiler,and connected in a particular way to it by wayof headers, I do not wishto be limited in these respects, as obviously other ways may be used.The only essential is that the tubes be .ar-

ranged between the furnace and the superheater elements without cuttingoff the radiation of heat to the superheater elements.

It will be understood that where the superheater tubes are not vertical,ythe protective water tubes are arranged parallel to them, nearer to thefurnace, and in line with the spaces between the superheater tubes, sothat the latter are exposed to the radiation'just as in the case of thevertical arrangement -used byway of illustration.

It will be noted that I rely for the protection of the superheaterelements principally, or almost entirely, on the difference in the rateat which the superheater elements and the water cooled tubes 17radiateheat.

, I do not rely on these tubes for cooling gases superheater comprisingparallel vertical alinedV superheater tubes adjacent to a wall of saidfurnace and water tubes parallel to the superheater tubes and in a planeparallel to and in advance'ofthe plane of the superheater tubes, saidsuperheater tubes being so located relatively to the water tubes and tothe furnace that they are exposed to direct radiant heat from saidfurnace.

2. In an apparatus of the class described, the combination of a furnace,a radiant type superheater comprising parallel vertical alinedsuperheater tubes adjacent to a wall of said furnace, Awater tubesparallel to the superheater tubes and in a plane parallel to and inadvanceof the plane of the superheater tubes, said superheater tubesbeing so located relatively to the water tubes and to the furnace thatthey are exposed to direct radiant heat from said furnace, upper andlower headers to which the water tubes are connected, and pipesconnecting them to the steam and water space of the boiler.

3. In an apparatus of the class described, the combination of a furnace,a radiant type superheater comprising parallel alined superheater tubesadjacent to a wall of said furnace and water tubes parallel to thesuperheater tubes and in a plane parallel to and in advance of the planeofthe superheater tubes, said superheater tubes being so locatedrelatively to the water tubes and'to the furnace that they are exposedto direct radiant heat from said furnace.

4. Inan apparatus of the class described, the combination of afurnace, aradiant type superheater comprising parallel vertical alined superheatertubes adjacent to a wall of said furnace and water tubes parallel to thesuperheater tubes and in a plane parallel to and inV advance of theplane of the superheater tubes, said superheater tubes being so locatedrelatively to the water tubes and to the furnace that they are exposedto direct radiant heat from said furnace, and that each superheater tubeis in close proximity to at least one water tube. j

5. In apparatus of the class described, the combination of a furnace, aradiant type superheater comprising parallel alined superheater tubesadjacent to a wall of said furnace, and water tubes parallel to thesuperheater tubes andarrangedin a plane adja-

